Clutch



G. M. EASON CLUTCH Filed March 25. 1937 2 Sheets-Sheet l June 11',1940.I c. NL EAsoN 2,203,862

CLUTCH Filed March 25 1937 2 Sheets-Sheet 2 Patented June 11, 1940CLUTCH Clarence M. Eason, WaukeshaWi`s., assignor to Industrial ClutchCompany, Waukesha, Wis., a

vcorporation of Wisconsi Application March `25, 1937,' s'rial No.132,986

1s claims. (o1. isa-ss) The present invention relates generally toclutches for releasably connecting a driving shaft to a driven shaft,and has to do more particularly with clutches of the type comprisingdriving and 5 driven members connected, respectively, to the driving anddriven shafts and adapted'for fric-l tional engagement with aninterposed coupling element, saidelement, when engaged withtsaid drivingand driven members, serving to tran'smit the drive, and when disengagedfrom one or both of said members providing for rotation of said drivingmember relative to said driven member,

`and without communicating such motion thereto.

jBroadly, one of the objects of the present invention resides intheprovision of a ,simple and sturdily constructed clutch of thecharacter described, wherein eitherV the driving or driven member isprovided with means ofv such a nature that the coeiiicient of frictionbetween such member and the coupling element will be higher than thecoemcient of friction between said coupling element and the othermember.

More specifically, one of the features .of the present invention residesinan arrangement of clutch wherein, when the clutch is out, the couplingelement is loosely carried with either the driving or driven member withwhich it has the lower coeflicient of friction and out of engagementwith the means on the\other member with which it has the higher coecient of friction,

the coupling element being sei ed by the aforementioned means on-'t eone driving or driven `member and held thereto by he application ofpressure in the initial stages \of letting in the clutch' whereby thedesired slippage of the clutch before final seizure occurs between thecoupling element and the member with which said element hasthe lowercoeicient of friction.

Another object of the invention resides in the 40 provision of a clutchwherein either the driving or'driven member is provided with means. inthe nature of an inflatable toroidal member which, when inated, expandsradially outwardly to connect said members and coupling elementtolsfgether in the manner hereinbefore described and, when/deiiated,will disconnect such members and element.

Still another object of the invention resides in the provision Vof aclutch wherein either the driving or driven member thereof is providedwith an air pressure controlled annular inatable tube of exiblerubber-like material which, when expanded, serves to effectively connectsaid members and coupling element together in torque transmittingrelation in the manner described,

said inflatable tube being arranged with respect tosaid driving ordriven member .to take the drive entirely through the side walls thereofand thereby provide an exceedingly flexible connection between saidmembers and coupling element 5 so as to accommodate practically any kindof misalignment between such members and element, and, moreover,cushioning the transmission of torque 'so asto dampen and eliminatetorsional vibration and the like. 1 l0 A further object of the inventionresides in providing "a clutch of the character described with acoupling element in the form of a dynamically balanced ring adaptedto beloosely carried by the drivingV or driven member `of the 15 Iclutch andformed of relatively loosely woven fabric which will stretch when wornand thereby maintain fairly close contact with its associated member.

A still further feature of the invention resides 20 in the provision ofsimple and `novel means for securing the annular inflatable tube to thedriving member of the clutch. l

These and other objects and advantages of the present invention will beapparent to those 25 skilled in the art afteraconsideration of thefollowing detailed description, taken `in conjunction with theaccompanying drawings.

, In the drawings:

Figure 1 is an .axial sectionl taken through a 30 clutch embodying theprinciples vof the present invention; and Figure 2 is an end inFigure1".l

VReferring now to the drawings, the reference numeral I0 indicates thedriving element 'or part; which is in the form of a ywheel II fastenedto the flange I2 of a motor crank shaft I3 by any suitable means, suchas cap screws I4. The liywheel II includes an overhanging flange I6having a circular friction surface Il against which a friction ringI8\is seated. The ring I8 is heldin place between a shoulder 20 formedon the flywheel and a spring ring 2l that is seated in a groove 22formed in the outer 45 edge of iiywheel flange I6. As best indicated in'view of thejclutch shownv Figure 2, one edge' of the groove 22 is cutout),

tool to remove the friction ring IB.

The friction ring I8 is formed of loosely woven friction material,similar to but softer than conventional brake lining stock. The ring i8is 55 Idiametrically opposite the stem 65.

preferably split, as at 21 in Figure 2 to provide for convenientinstallation of the ring without having to disassemble any of the clutchelements. After installation, however, it is preferable to have the endsof the ring I8 fastened together by any suitable means, such as aconventional belting fastener 28.

The driven element of the clutch is indicated in its entirety by thereference numeral l35 and comprises a driven shaft 36 having a reducedend 31 to which a clutch hub 38 is securely fastened, as by a key 39 orthe equivalent. The clutch hub 38 is held up against a shoulder 42 onthe shaft 36 by means of a ring or washer 43 having an opening receivinga threaded stud 48 and engaging in a recess 45 formed on the inner endof the hub 38. A nut.46 is threaded onto the stud 44 and when tightenedholds the clutch hub 38 rmly against the shoulder 42.

The clutch hub 38 is provided with a radial flange 58 that has aplurality of threaded [bosses receiving cap screws 52 which serve tofasten a member 54 formed of pressed steel or the like and which has aradially inwardly disposed flange 55 with apertures 56 receiving the capscrewsv 52. The rim portion 51 of the member 54 serves as a mounting foranannular inflatable member 68 which is preferably in the nature of apneumatic ring formed of tire stock and vulcanized, as at 6I, to theouter surface of the rim 56 so as to be securely bonded thereto. Themember 68 normally takes the position shown in full lines in Figure 1and has a flattened circumferential section 62 adapted to engage thefriction ring I8 when the member 68 is inflated. The member 68 has astern 65 that extends radially inwardly through an opening 66 formed inthe rim 55 and is disposed about the. outer end of a pipe nipple 61, theinner end of which is threaded, as at 68, and screwed into the outer endof a bore 69 formed in the hub member 38 and which is in register with aradial duct 18 formed in the inner end of the driven shaft 36. An axialbore 1I communicates with the registering bores 69 and 18 and extendslongitudinally of the driven shaft 36 to and into communication withanother bore 13 formed in the driven shaft 36 outwardly of the clutchhub 38. A hose clamp 14 is disposed about the end of the stem 65 and.serves to clamp the latter to the outer end of the pipe nipple inleak-tight relation.

A bushing 15 is disposed between the outer end of the clutch hub 38 anda shoulder 16 formed on the driven shaft 36. Thebushing 15 is in thenature of an anti-friction member receiving a collar 18, one end ofwhich is closed by a cap 19 fastened to the main body of the collar 18by cap screws 88. A fitting 8I provides for convenient lubrication ofthe collar 18. 'I'he collar 18 and the cap 19 are constructed so as toform an interior annular chamber 82 communicating with the shaft bore13. The ends of the chamber 82 are closed by packing elements 84 in thenature of leather cups seating against the shaft 36 in leak-tightrelation. An air pipe 98 is threaded into the collar 18, as at 9i, andis adapted to conduct air or other fluid under pressure into the chamber82 and associated ducts and bores.

To balance the stem 65, pipe nipple 61, and associated parts, acounterweight 94 is riveted or otherwise secured to the rim 56, at apoint 'I'he central portion of the member 54 is provided with aplurality of openings 96, and similar openings aeoaeea f' 91 are formedin the web of the flywheel II for the puxlpose of promoting aircirculation through the clutch, as indicated by the arrows.

The operation of the clutch described above is substantially as follows:When the clutch is disengaged the inflatable member 68 normally occupies the position shown in full lines, with the clutching surface 62thereof spaced from ,the friction ring I8. Air under pressure controlledin any suitable manner is admitted through the pipe 98 and the bores andducts leading to the stem 65. This air pressure expands the inflatablemember 68 and causes the periphery 62 thereof to move radially outwardlyinto engagement with the friction ring I8. The latter is loosely mountedbetween the shoulder 28, the clutching surface I1, and the spring ring2'4, so that at the instant of Contact between the periphery 62 of themember 66 and the ring I8, the latter is gripped by the member 68 andslips along the clutching surface I1. In order to secure this action,the material of which the friction ring I8 and the inflatable member 68are formed is so chosen as to provide a coefficient of friction betweenthe member '68 and the ring I8 which is several times greater than thecoelicient of friction between the ring I8 and the flywheel II. ily, theratio is in the neighborhood of three to one. As air pressure continuesto be admitted through the inlet pipe 98, the'member 68 expandsradiallyoutwardly with increasing force so as totransmit increased amounts oftorque from the flywheel II to the driven shaft 36. However, allslippage at this time occurs between the friction ring I8 and theflywheel II, which relieves the member 68 of wear, as might occur if anyslippage took place between the member 68 and the friction ring duringthe engaging of the clutch. As air pressure builds up within the member68 the friction ring I8 is eventually forced radially outwardly into frmnon-slipping engagement with the surface I1 of the flywheel II,whereupon the shaft 38 will be driven at the same speed as the flywheelI I.

When firm engagement is thus established, it will be observed that thereis no metallic or rigid connection of any nature whatsoever between theflywheel II and the driven shaft 36. If the latter is out of alignment,either radially, axially, angularly or f otherwise, such misalignment iseasily accommodated by the yielding of the flexible walls of the member68. A clutch constructed according to the principles of the presentinvention admirably accommodates. any degree of misalignment, whereasclutches having a rigid connectifn between the driving and driven ele-Preferably, although not necessarf ments are usually renderedunserviceable within f a relatively short time if there should be even asmall misalignment between the driving and driven parts. Any tendencyfor the member 68 to heat, due to the flexing of the walls thereof, istaken care of by the air circulation through the' openings 96 and 91.

,f To release the clutch, the air pressure within the member 68 isreleased, or if desired, sub-atmospheric pressure may be imposedupon theinterior of' the member 68, so that the peripheral portion 62 thereofdraws away from the friction ring I8. During this releasing operation,any slippage that occurs takes place betw'een the friction ring I8 andthe flywheel, and not between the friction ring I8 and the member 68.

Any suitable means 'may be provided for inating and deflating the member68 for engaging and disengaging the clutch. A clutch constructedaccording to the principles of the present invention may be 4employed inalmost any installation where a clutch is needed. However, my clutch isparticularly advantageous when used'in connection with air compressormachini ery, since a source of air under pressure for operating theclutch is conveniently accessible at all times.

While I have shown-and described above the principal objects of thepresent invention, it will be apparent to those skilled in the art thatmy invention is not to be limited to the specific details shown anddescribed above, but that, in fact, widely different means may beemployed in the practice of the broader aspects of my invention. i

What I claim, therefore, and desire to secure by Letters Patent is:

1 In a clutch adapted to connect a flywheel and a driven shaft, saidflywheel having a clutching surface, the combination of a driven clutchmember secured to said shaft, an inflatable, `member securely fastenedto said driven clutch member, and a friction ring loosely seated againsttheclutching surface of said flywheelV and having an internal diametergreater than the external ."diameter` of said inflatable member when thelatterY is deflated, whereby said friction ring rotates ,withsaidywheeLand means providing forthe inflation of said inflatable member, thecoeilicient` of friction between said inflatable member and:,saidfriction member `being greater thanthe co` efficient of frictionbetween the friction member and said flywheel, whereby said frictionmem-- ber, moves withsaid inflatable member when 'contactltherebetween`is established by the` ination thereof, further inflation ofsaidinflatableV fmember serving to cause said friction ring to ygriprtheilywheelso as to transmit torque vtherefrom' through said inflatablemember to `said driven member.

2 Aclutch,` adapted to connect a flywheel to la` drivenshaft; comprisinga driven member secured to said shaftand having a vrim section, a

i flattened toroidal hollow member having flexible walls and securelybonded to said rim section, the outer peripheral portion of said hollowtoroidal member being substantially cylindrical, and a generallycylindrical friction ring loosely carried by the flywheel normally outof contact with `said hollow member, said ring being split to facilitateremoval and replacement thereof about H ,"said driven shaft and intoposition between said toroidal member and the flywheel, and means to i,secure the ends of said split ring together after i openings. andadapted when expanded to frictionally engage the clutch surface of theflywheel and connect the driven shaft to the latter, said air openingsproviding for a circulation of cooling air at points adjacent saidexpansible member.'

4. As a means for releasably coupling a driving part to a driven part, afriction clutch comprising a driving member and a driven member, eachbeing adapted to be connected to one of said parts, a coupling elementloosely disposed between and adapted to transmit the drive between saidmembers, means carried by one of said members for engagement with saidcoupling element and having a coefficient of friction with said elementthat is higher than the coefficient of friction between said couplingelement and the other member, said coupling element being looselycarried with the member with which it has the lower coefficient offriction and being 'out of engagement with the means on the other memberwith which it has the higher coeil'cient when the clutch is disengaged,and means for forcing said last mentioned means radially into frictionalengagement with said coupling element so as to connect said clutchmembers through said coupling element and the means engageabletherewith.

5; The combination of claim 4 wherein the driving and driven members areconcentric and the coupling element comprises a dynamicallybalanced'expansible ring.

6; The-combination of claim 4 wherein the means vcarried by one of saidmembers for eni gagement with said coupling element comprises an elasticinflatable ring.

7. The combination of claim 4 wherein the a'n `elastic/inflatable ringhaving a rubber fricly balanced expansible ring of fabric of relativelyloose weave.l

8` The combination of claim 4 wherein the coupling element comprisesadynamically balanced` expansible ring formed from a single length ofmaterial and having its outer and inner surfaces-directly engageable byone of said driving or driven members and the means carried by the otherof said members, respectively.

9. In fa clutch adapted to connect a flywheel and a driven shaft, saidflywheel having a clutching surface, the combination of a driven clutchmember secured to said shaft, an inflatable member securely fastened tosaid driven clutch member, and a friction ring loosely seated againstthe clutching surface of said flywheel and having an internal diametergreater than the external diameter of said inflatable member when thelatter is deflated, whereby said friction ring rotates with saidflywheel, and means providing for increasing the pressure within saidmember to expand the same'and cause said friction ring to grip` theflywheel so as to transmit torque therefrom` through said inflatablemember to 'said driven member.

10. A clutch comprising driving and. driven members, a hollow expansiblering having flexible side Walls and securely fastened to one of saidmembers, an annulusdisposed between the other member and said ring, saidannulus being separate from said ring and having a diameter more nearlyequal to the diameter of the adjacent portion of said other member thanis the diameter of the adjacent portion of said ring, whereby saidannulus normally rotates with said means carried by one of said memberscomprises other member, expansion of said ring serving to vforce theannulus into engagement with the members together, and means forexpanding said ring to connect said driving and driven members.

11. A clutch adapted to connect a flywheel to a driven shaft, comprisinga light weight pressed metal driven member secured to said shaft andhaving a rim section, a flattened toroidal hollow member having flexiblewalls and securely bonded to said rim section, the outer peripheralportion of said hollow toroidal member being substantially cylindrical,and a generally cylindrical friction ring loosely carried by theiilywheel normally out of Contact with said hollow member, the expansionof said toroidal member serving to force said friction ring intofrictional engagement with said flywheel to connect the driven shaftthereto.

12. A clutch comprising driving and driven members, a hollowpneumatically expansible ring having exible side walls and securelyfastened to one of said members, an annulus disposed between the other.member and said ring and normally out of contact with the latter,expansion of said ring serving to engage and force the annulus radiallyinto engagement with theother member to connect said driving and drivenmembers together, and means providing aeoaeea increasing the internalpressure in said hollow member to expand the same and connect saiddriving and driven members.

13. In a clutch adapted to connect a driving partto a driven part spacedapart radially, an inilatable member securely fastened to one of saidparts, the other part having a clutching surface adjacent saidinflatable member, and a friction ring seated adjacent said clutchingsurface and having a diameter such that the friction ring tends torotate with the radially outer of saidparts, the coefficient offrictionfor said inflatable member and said friction ring being greaterthan the coeflicient of friction for said in ata-ble member and saidother part, whereby relative .'movement takes place between saidfriction ring and said other part when the clutch is engaged, and meansproviding for the inflation of said inflatable member, said meansincluding a slip connection to accommodate rotation of said one part,`inflation of said inflatable member serving to cause said friction ringto grip said surface so as to transmit torque from the driving anddriven parts through said inilatable member.

CLARENCE M. EASON.

